As is known, the need for collective protection has recently increased, due to the threat of military attacks and acts of terror using methods and components of chemical or biological warfare. The problem that a contamination-protected space is enclosed always exists; people have to be able to enter and leave a mobile shelter or tent without harming the atmosphere within. One method of solving this problem is to use shelters or protected spaces in which an airlock chamber serves as the entrance or exit. Such an airlock chamber should not only have airlock characteristics, but also should enable decontamination. All contamination adhering to persons and/or other elements entering the protected space must be flushed off as effectively as possible, thereby assuring that no contaminated air will enter the protected space.
To date, air-tight tents having an integrated airlock chamber have not provided effective decontamination within a short period of time. The decontamination method used in prior art shelters of this type is to push clean air into the airlock chamber on one side and to pass it through the airlock chamber, preferably diagonally, to leave the chamber via holes in the wall opposite to the air inlet. The disadvantages of this method are that the airflow has too much turbulence and the length of time needed for decontamination is too long. As a result, the use of such airlock chambers for decontamination is limited. Furthermore, the entrance procedures for using these chambers and their ability to accommodate large numbers of individuals, are also complicated.